• Title/Summary/Keyword: UV reactor

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Study on CFD Methodology for a Open Channel Type UV Reactor (전산유체역학을 활용한 개수로형 UV소독장비의 해석기법 연구)

  • Hwang, Woochul;Bak, Jeong-Gyu;Kim, Hyunsoo;Lee, Kunghyuk;Cho, Jinsoo
    • The KSFM Journal of Fluid Machinery
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    • v.18 no.2
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    • pp.54-59
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    • 2015
  • The performance of UV reactor which is used in water treatment is strongly affected by UV fluence rate and water flow in the UV reactor. Therefore, CFD tools are widely used in designing process of UV reactors. This paper describes the development of a computational fluid dynamics (CFD) methodology that can be used to calculate the performance of open channel type UV reactor used in wastewater treatment plant. All computations were performed using commercial CFD code, CFX, by considering three dimensional, steady, incompressible flow. The Eulerian-Eulerian multi-phase method were used to capture the water-air interface. The MSSS model, provided by UVCalc3D, was used to calculate the UV intensity field. The numerical predictions and calculated UV Dose were compared with experimental dataset to validate the CFD methodology. The reactor performance based on MS2 log reduction was well matched with measurements within 6%.

A Study on CFD Methodology of the Performance Predictionfor the UV Disinfection Reactor (자외선 소독기 성능 예측을 위한 CFD 해석 기법 연구)

  • Kim, Hyunsoo;Bak, Jeonggyu;Lee, Kunghyuk;Cho, Jinsoo
    • The KSFM Journal of Fluid Machinery
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    • v.17 no.6
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    • pp.44-51
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    • 2014
  • The disinfection method using UV has emerged as photodissociation in water disinfection. In order to predict performance for UV disinfection, CFD analysis was performed due to saving cost. Most CFD studies of UV reactor have used particle tracking method. However it demands additional analysis time, computing resource and phase besides working fluid. In this paper, pathogenic microorganisms' route is assumed to streamline of fluid to save computing time. the computational results are in good agreement with experimental results. The results of streamline method are compared with the particle tracking method. In conclusion, the effectiveness of streamline method for UV disinfection are confirmed.

UV Dose Predictions for Ultra Violet Flowing Water Purification of Axial Reactor Type based on the location of the exit by CFD (CFD에 의한 Axial Reactor Type 자외선 유수살균장치의 출구 위치에 따른 UV Dose 예측)

  • Choi, Jong-Woong;Kim, Seong-Su;Park, No-Suk;Lee, Young-Joo;Chae, Seon-Ha
    • Journal of Korean Society of Water and Wastewater
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    • v.26 no.4
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    • pp.521-533
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    • 2012
  • Interest in application of ultraviolet light technology for primary disinfection that used for the treatment of water for consumption and wastewater has increased significantly in recent years. Analysis of these systems has been carried out using Computational Fluid Dynamics (CFD) procedure. It offers advantages over other techniques in specific circumstances. CFD has emerged as a powerful tool to aid design of a UV reactor by providing the UV dose delivered by the proposed reactor design and allowing engineers to evaluate alternative designs in much less time and at a reasonable cost. In this study, five different configurations of the apparatus depending on the location of the exit are evaluated in terms of maximum dose, minimum dose, flow patterns, particle tracks and transient dose. The configuration 3 results have higher minimum UV dose value and uniform particle distribution of the UV dose on the outlet than other's.

Removal Characteristics of Single and Binary Vapors of Acetone, Toluene, and Methyl Mercaptan by Cylindrical UV Reactor Installed with TiO2-Coated Perforated Plane (TiO2를 코팅한 다공판을 설치한 원통형 UV 반응기에 의한 아세톤, 톨루엔, 메틸메르캅탄 단일 증기 및 2성분 혼합증기의 제거특성)

  • Jeon, Jin-Woo;Kam, Sang-Kyu;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.24 no.3
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    • pp.317-322
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    • 2015
  • The photocatalytic decomposition characteristics of toluene, acetone, and methyl mercaptan (MM) by UV reactor installed with $TiO_2$-coated perforated plane were studied. The removal efficiency of single toluene, acetone, and MM vapor was increased with increasing oxygen concentration, but decreased with increasing inlet concentration. Elimination capacity of single toluene, acetone, and MM vapor was obtained to be $628g/m^3{\cdot}day$, $1,041g/m^3{\cdot}day$, and $2,158g/m^3{\cdot}day$, respectively. Also, the photocatalytic decomposition of binary vapor consisted of toluene and acetone, toluene and MM, acetone and MM were observed. Elimination capacity of toluene mixed with acetone, toluene mixed with MM, acetone mixed with toluene, acetone mixed with MM, MM mixed with toluene, and MM mixed with acetone was $327g/m^3{\cdot}day$, $512g/m^3{\cdot}day$, $128g/m^3{\cdot}day$, $266g/m^3{\cdot}day$, $785g/m^3{\cdot}day$ and $883g/m^3{\cdot}day$, respectively. The inhibitory effect of acetone was higher than MM in photocatalytic decomposition of toluene, the inhibitory effect of toluene was higher than MM photocatalytic decomposition of acetone, and the inhibitory effect of toluene was higher than acetone in photocatalytic decomposition of MM.

A Study on the Degradability of Pharmaceuticals during UV Treatment (자외선 처리시의 의약품류의 분해도에 관한 연구)

  • Kim, Ilho
    • Journal of Korean Society on Water Environment
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    • v.28 no.6
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    • pp.902-910
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    • 2012
  • The photodegradation characteristics of 30 pharmaceuticals were investigated by batch experiments using Ultraviolet (UV) reactor. The investigated pharmaceuticals include antibiotics, analgesics and antiarrhythmic agents etc. Tested water was prepared by simultaneously spiking 30 pharmaceuticals into pure water, and each experiment was conducted using 3 types of UV lamps. As a result, batch experiments showed that reactions of all the investigated pharmaceuticals followed pseudo-first order reaction regardless of the applied UV lamps. Among the pharmaceuticals, Cyclophosphamide, 2-Quinoxaline carboxylic acid and Clarithromycin proved to be the most UV-resistant compounds. Contrarily, Ceftiofur, Diclofenac and Ketoprofen were easily degraded by all the UV lamps. Dissolved organic carbon (DOC) concentration hardly changed although the concentration of the pharmaceuticals concentration gradually decreased with time, indicating that the degradation of parent pharmaceuticals may produce their intermediates during UV treatment.

Sterilization of Escherichia coli Based on Nd: YAG Resonator with a Pulsed Xenon Flashlamp

  • Kim, Hee-Je;Kim, Dong-Jo;Hong, Ji-Tae;Xu, Guo-Cheng;Lee, Dong-Gil
    • Journal of Electrical Engineering and Technology
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    • v.6 no.2
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    • pp.275-279
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    • 2011
  • Sterilization of Escherichia coli (E. coli) is examined using a unique pulsed ultra-violet (UV) elliptical reactor based on Nd:YAG laser resonator, UV radiation from a pulsed xenon flashlamp. The light from the discharge has a broadband emission spectrum extending from the UV to the infrared region with a rich UV contained. Sterilization method by using the UV light is fast, environment-friendly and it does not cause secondary pollution. A Nd:YAG laser resonator having elliptical shape has advantage of concentrating the radiation of the UV light at two foci as the quart sleeve filled with E. coli. The primary objective of this research is to determine the important parameters such as pulse per second (pps), the applied voltage for sterilizing E. coli by using an UV elliptical reactor. From the experiment result, the sterilization effect of UV elliptical reactor is better than that of UV cylindrical reactor, and it can be 99.9% of sterilization at 800V regardless of the pps within 10 minutes.

A Study on Optimal Design of UV Contactor using an Optical Radiation Model (광학모델을 이용한 자외선 접촉조 최적 설계에 관한 연구)

  • Choi, Younggyun;Kim, Dooil;Kim, Sunghong
    • Journal of Korean Society on Water Environment
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    • v.25 no.4
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    • pp.547-552
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    • 2009
  • Because of refractory property of light, the travel path of UV light becomes longer than the straight line and shorter solely in water as UV light passes sequentially through air, quartz and water. Note that water significantly absorbs UV light. Hence, UV intensity shall be estimated to be lower when refraction is neglected than it is considered. Reflection is also critical for the design of UV radiation system. While the reflection at the interface of air and quartz is low enough to ignore, it is too high to be ignored at the interface of quartz and water. Assuming constant power, smaller length to width ratio of UV reactor is beneficial and single-lamp system is preferred to multi-lamps. Under the given cross section, optimal lamp positions could be decided. For example of an elliptical reactor with dual lamps, the optimal lamp locations shall be the 1/3 and 2/3 position of the longer axis.

Effect of Benzene, Acetone, and Methyl Mercaptan Vapor on Photocatalytic Decomposition of Toluene Vapor (톨루엔의 광촉매 분해시 벤젠, 아세톤 및 메틸메르캅탄 증기가 미치는 영향)

  • Kam, Sang-Kyu;Jeon, Jin-Woo;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.23 no.12
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    • pp.1971-1976
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    • 2014
  • In this study, the photocatalytic decomposition characteristics of single toluene, toluene mixed with benzene, toluene mixed with acetone, and toluene mixed methyl mercaptan (MM) by UV reactor installed with $TiO_2$-coated perforated plate were studied. The photocatalytic decomposition rate of single toluene, toluene mixed with benzene, toluene mixed with acetone, and toluene mixed with MM fitted well on Langmuir-Hinshelwood (L-H) kinetics equation. The maximum elimination capacity was obtained to be $628g/m^3{\cdot}d$ for single toluene, $499g/m^3{\cdot}d$ for toluene mixed with benzene, $318g/m^3{\cdot}d$ for toluene mixed with acetone, and $513g/m^3{\cdot}d$ for toluene mixed with MM, respectively. The negative effect in photocatalytic decomposition of toluene are found to be in the order of acetone>benzene>MM.

Effect of Methyl Ethyl Ketone and Ethyl Acetate Vapor on Photocatalytic Decomposition of n-Pentane Vapor (n-Pentane 증기의 광촉매 분해 시 Methyl Ethyl Ketone 증기와 Ethyl Acetate 증기의 영향)

  • Kam, Sang-Kyu;Jeon, Jin-Woo;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.23 no.6
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    • pp.1151-1156
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    • 2014
  • The photocatalytic decomposition characteristics of single n-pentane, n-pentane mixed with methyl ethyl ketone (MEK), and n-pentane mixed with ethyl acetate (EA) by cylindrical UV reactor installed with $TiO_2$-coated perforated plane were studied. The effects of the residence time, the inlet gas concentration, and the oxygen concentration were investigated. The removal efficiency of n-pentane was increased with increasing the residence time and the oxygen concentration, but decreased with increasing the inlet concentration of n-pentane. The photocatalytic decomposition rates of single n-pentane, n-pentane mixed with MEK, and n-pentane mixed with EA fitted well on Langmuir-Hinshelwood kinetics equation. The maximum elimination capacities of single n-pentane, n-pentane mixed with MEK, and n-pentane mixed with EA were obtained to be $465g/m^3{\cdot}day$, $217g/m^3{\cdot}day$, and $320g/m^3{\cdot}day$, respectively. The presence of coexisting MEK and EA vapor had a negative effect on the photocatalytic decomposition of n-pentane and the negative effect of MEK was higher than that of EA.

Applications of a Hybrid System Coupled with Ultraviolet and Biofiltration for the Treatment of VOCs (휘발성유기화합물 처리를 위한 고도산화법과 고분자 담체 바이오필터 결합시스템의 적용)

  • Shin, Shoung Kyu;Song, Ji Hyeon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.4B
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    • pp.441-447
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    • 2008
  • Volatile organic compounds (VOCs) emitted from various industrial sources commonly consist of biodegradable chemicals and recalcitrant compounds. Therefore, it is not effective to employ a single method to treat such mixtures. In this study, a novel hybrid system coupled with a ultraviolet (UV) photolysis reactor and a biofilter in a series was developed and evaluated using toluene and TCE as model VOCs. When only TCE was applied to the UV reactor, greater than 99% of TCE was degraded and the concentration of soluble byproducts from photo-oxidation reaction increased significantly. However, the toluene and TCE mixture was not effectively degraded by the UV photo-oxidation standalone process. The hybrid system showed high toluene removal efficiencies, and TCE degradation at a low toluene/TCE ratio was improved by UV pretreatment. These findings indicated that the UV photo-oxidation were effective for TCE degradation when the concentration of toluene in the mixture was relatively low. A restively high toluene content in the mixture resulted in an inhibition of TCE degradation. Thus, chemical interactions in both photo-oxidation and biodegradation need to be carefully considered to enhance overall performance of the hybrid system.

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